1. Field of the Invention
This invention relates to an apparatus and method for synchronizing and outputting image data.
2. Description of the Related Art
When image processing is executed using a portion of an image composed of a plurality of horizontal lines of an image of one frame, as in the manner of digital filtering processing, it is necessary to store temporarily one horizontal line""s worth of image data using a line memory and to execute synchronization processing. Image processing is executed using the one line""s worth of image data that has been stored temporarily in the line memory and the succeeding line of image data, which has not been directed through the line memory.
CCDs having greater numbers of pixels are being produced, and the number of pixels on one horizontal line has become extremely high. The inevitable outcome is an increase in the capacity of the line memory that stores one horizontal line""s worth of data. There is an increase also in the cost of the line memory and in the power consumed by the line memory itself.
Accordingly, an object of the present invention is to realize the synchronization processing of image data without increasing the capacity of a line memory.
According to the present invention, the foregoing object is attained by providing an image data synchronizing apparatus comprising an extraction device for extracting one horizontal line of image data in a plurality of image areas, which are obtained when one frame of an image has been divided in the horizontal direction, on a per-image-area basis from applied image data representing one frame of the image; and a line memory for storing temporarily the image data that has been extracted by the extraction device, the line memory having a capacity for an amount of data approximately equal to that of the one horizontal line of image data in each image area.
The present invention provides also a method suited to the apparatus described above. Specifically the method comprises the steps of: extracting one horizontal line of image data in a plurality of image areas, which are obtained when one frame of an image has been divided in the horizontal direction, on a per-image-area basis from applied image data representing one frame of the image; storing the extracted image data temporarily in a line memory having a capacity for an amount of data approximately equal to that of the one horizontal line of image data in each image area; and outputting the image data from the line memory.
In accordance with the present invention, one line""s worth of image data in a plurality of image areas, which are obtained when one frame of an image has been divided in the horizontal direction, is extracted on a per-image-area basis from applied image data representing one frame of the image. The extracted image data is stored temporarily in the line memory and is then output from the line memory.
Thus the extracted item of image data and the item of image data that has been stored temporarily in the line memory and read out of the line memory are obtained simultaneously.
According to the present invention, it will suffice if the capacity of the line memory that stores the image data is large enough to store one line""s worth of image data of one image area. Since it is unnecessary to store one horizontal line of image data of one entire frame of an image, the capacity of the line memory can be reduced. This means that even if the CCD for obtaining the image data is provided with a large number of pixels, synchronization processing can be achieved using a line memory having a small capacity.
An arrangement may be adopted in which the mutually adjacent portions of neighboring image areas are overlapped.